Switch inclosure



A. P. BALL. mam 34 SWITCH INCLOSURE Filed Oct. 17, 1921 2 Sheets-Sheset l l talented ill, i929.

run T s ALBERT 1?. BALL, OF DETROIT, MICHIGAN, ASSIGNOR TD SQUARE 1) COMPANY, OF DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN.

SWITCH INCLOSURE.

Application filed Getober 17, 1921. Serial No. 508,413.

My invention relates to an inclosed switch, and it has especial relation to devices of the character described wherein the switch inclosure is composed entirely of insulating material.

In so far as I am aware switch inclosures have heretofore been composed of metallic material and have embodied therein an insulating base upon which the conducting con tact members are mounted. Such a structure necessitates. the provision of considerable clearance space between the conducting portions of the switch and the conducting surface of the switch inclosure to meet certain fixed requirements.

I propose, therefore, to provide a switch which shall embody an inclosure composed entirely of insulating material whereby certain advantages are realized. Of course many considerations enter into, and contr1bute to the novelty of, a switch constructedof insulating material in accordance with my invention. Having determined on such a construction there are many diiliculties to be overcome before a switch inclosure composed of insulating material, and in the illustrated embodiment of porcelain, can be made. How the solution of these problems are interwoven in the novel embodiment of a switch inclosure will be more fully hereinafter pointed out.

In such a switch the clearance between the live material parts thereof and the interior of the casing may be reduced to a negligible minimum, in fact the casing need only be large enough to satisfactorily contain the switch elements. I find thata switch of this character possesses marked commercial advantages in that it may be made for an appreciable less cost than the same switch mounted on a porcelain base, the latter in turn being inclosed in a steel cabinet. Not only is an additional porcelain base eliminated, but the inclosure is at the same time rendered entirely safe since, irrespective of the electrical circuit conditions, the exterior of the inclosure can not be energized with the resultant danger to those who must come in contact therewith. Not only is the metallic inclosure dispensed with, but all of the other metallic parts are reduced to a minimum, both as to number and size.

In the latter connection I also provide a. novel device for grounding all of the metal parts in connection with a switch. except those which are alive, or through which the closure is quite important since it contributes to the practicability of the device and insures that the cover can be slammed open or shut with considerable force Without there being any chance of the structure being broken. Of course the above considerations are only pertinent when the insulating material which is employed is frangible in character, and it is to be understood that I do notlimit myself to forming the inclosure of the latter character; it being well within the spirit of my invention to mold all of these parts of the inclosure from a material which, although insulative in character, is not at all frangible or subject to easy breakage.

Various other advantages of my improved switch inclosure, as well as any accessory device which may be associated therewith, will be better understood after a consideration of the ensuing description thereof, taken in connection with the accompanying drawings; in which:

Figure 1 is a plan view of a switch inclosure embodying my invention, a terminal protecting hood being associated therewith in a novel manner;

Fig. 2 is an elevational sectional view taken on the line 2--2 of Fig. 1; and,

Fig. 3 is another elevational sectional view taken on the line 33 of Fig. 1.

Referring now more particularly to the drawings, a switch inclosure constructed in accordance with my invention comprises an integrally molded box portion 10 and an integrally molded cover portion 11, both being composed entirely of insulating material and being provided with cooperatin hinged portions 191- 12 and 13, whereby t e two members may be secured together to form a complete boa. Mounted within the box are stationary contacts 1d and 15, the same being adapted to be bridged by a movable contact 16. The latter is moved to and from bridging position by an operating member 17, which is pivotally mounted in the casing in a novel manner. One end 18 of the member 17 is pivoted directly in the insulating wall of the casing, whereas the other end 19 of the operating member is journalled in a metallic member 20, which is secured to the side of the box, as best shown in Fig. 3, the lower end thereof being bent around flush with the bottom of the box and secured in position by a screw 21. Washers 22-22 and cotter pins 2323 serve to secure the right hand end of the operating member 17 as shown. It will be noted that the side 0 the box is slotted from the top edge downwardly as at 24 to permit the operating member 17 to pass therethrough, and that said elongated aperture is entirely closed by the member 20.

It should be noted that the contacts 14 and 15 are mounted directly on the bottom of the switch inclosure, as are also the fuse receptacles 25. A lug 26 is molded in the bottom of the box and serves to limit the switch opening movement of the member 17 by contacting with a lug 27, the latter serving to connect the movable blade 16 and the said operating member 17. In this connection it should also be observed that the walls of the inclosure are very close to the live contacts and it should be remembered that this is possible only because of the insulative character of said enclosure.

The member 20 extends upwardly a considerable distance beyond the upper edge of the box portion of the inclosure and is formed at the top 28 to comprise a spring latch, an car 29 being struck inwardly therefrom, as shown. On the cover of the box is mounted a member 30 which cooperates with the upper portion 28 of the metallic member 20, and which is provided with a hole 31 into which the latch 29 extends when the cover is closed. It is therefore necessary when opening said cover to spring the member 28 to the right (see Fig. 3) and Withdraw the ear 29 from the cooperating hole 31. Moreover, holes 32 and 33 are provided in members 28 and 30, respectively, whereby the bail of a padlock may be passed therethrough, if desired, and

the cover of the switch permanently lockedclosed. It will be observed that the member 30 is seated in a depressed portion 34; in the cover of the switch inclosure. The only metallic parts of the switch, therefore, other than the live contact parts through which the current flows, are the member 30, its attaching screw 30, the cooperating latch member 20, the screw 21 and the operating member 17. I have provided, therefore, a bind in post 35, b means of which all of the metallic parts 0 the switch, other than the live parts, may be grounded whereby all danger of even t e minimum number of metallic parts, which are associated with the switch, becoming alive is eliminated.

The upper part of the cover of the 'swith has a portion 36 molded thereinto which cooperates to lock the switch operating member 17 into open position, when the latter is thrown to its extreme postion. When in the latter position the member 27 is against the lug 26 and the member 17 is held down by the lug 36 whereby substantially no movement of the moving parts of the switch is permitted. This locking open of the switch is particularly advantageous when it is de sired to prevent the use of current, since the closing and locking of the box when the switch contacts are in extreme open position locks the latter in that position.

The bottom of the insulating inclosure is pierced with a plurality of screw holes 37 through which screws such as 38 may be passed to secure the box to a supporting surface, such as a wall. A boss 37 is formed around the exterior of these holes, as shown.

In the hinged portions 12 of the body of the inclosure are formed recesses 39 in which may be positioned shock absorbing elements, in this case being shown as rubber plugs 10, the heads of which protrude beyond the plane portion 12 (see Fig. 3) and thus absorb the shock when the cover of the box is slammed open. Other recesses 11-41 are formed on the interior of the cover and contain analogous bumper elements 42- 12 which are adapted. to contact with the edges of the box proper when the cover is slammed shut. The provision of these bumper elements eliminates any chance of the box being injured by careless handling thereof.

A conduit adapter 43 is adapted to be positioned at either end of the box and it will be observed that the surface of said box is de-- pressed at 14- 14 to receive the inner end of this adapter. The same is secured to the inclosure by one of the screws 38, an attaching portion 45 of the adapter fitting around one of the raised portions 39 whereby the entire aggregate may set flush against a supporting wall. The adapter in this case comprises two portions, one being formed from a stamping which comprises the said bottom end and walls, while the top 46 thereof is held in position by an over-turned lug and screw 17. The top of the adapter can only be removed when the top of the inclosure is opened, it being observed in Fig. 2 that the edge of the box cover fits down against the inner edge of the top, whereby the mere removal of the screw 47 will not permit of the removal of the top of the conduit adapter. The last adapter itself cannot be tampered with unless the cover of the inclosure is open. I consider this inter-association of devices as quite important, since it permits of the realization of advantages which would not otherwise :iu-' 7 llii lit)

described means insures that the r here to the combination. The end wall of -the adapter, as well as the side and bottom walls thereof, are provided with lrnocloouts which may be removed so that the conduit through which the wires run may enter the adapter and be securely fastened to it by the usual means of a lock-nut and bushing.

From the above description, it will be apparent that I have realized many advantages by providing a wholly insulative inclosure for electrical switches. \Vorkers in the switch art have always, in so far as I am aware, regarded the making of a switch inclosurc out of porcelain as an entirely impracticable matter, and one which did not merit any thought. Irrespective of this feeling, however, I have found that by utilizing the material, as hereinbefore set forth, and particularly by providing means which protect the inclosure against violent jars, an inclosure having undoubted advantages is eventuated. The saving in cost alone is worthy of notice since, as I have hereinbefore intimated, the inclosure need only be large enough to contain the switch elements, and all of that material and space, which has heretofore been necessary to provide clearance between the live metal parts of the switch and the metal inclosure, are saved. Moreover, it should be understood that my switch inclosure can be very simply and quickly molded whereby it can be manufactured at a very low cost and with comparatively unskilled labor.

Because of the manner in which I construct this switch it is a comparatively easy matter to ground all of the metal parts thereof, something-which cannot be expeditiously performed with switches which are inclosed in metallic cabinets. All of the difficulties heretofore inherent in the mounting of live contacts on a conducting base are eliminated, since the manufacturer is no longer called upon to insulate the two portions of the switch, just mentioned, from each other. And here again the mounting of the contacts directly on the insulative base, which is itself a portion of the inclosure, contributes many advantages incident to my switch. I find a switch of this character is entirely safe to the unskilled workman, since no amount of disruption of the circuits, with which it is associated, can so energize the outer surface of the inclosure as to constitute a source of danger to those who may come into contact with said switch inclosurc.

lVhilo I have described but one embodiment of my invention it is obvious that many -1noditications thereof may occur to those skilled in the art and I desire, therefore, that my invention be limited only by the showing of the prior art and by the scope of the appended claims.

What I now claim as new and desire to obtain by Letters Patent of the United States is:

1. A switch inclosure comprising a orcelain box, a porcelain cover, and metal atching members mounted on said box and cover, one of said latching members serving as a support for a switch 0 crating member.

2. A switch inc osure comprising a box molded integrally from insulating material and a cover therefor likewise integrally molded from an insulating material, contacts of conductive material mounted directly on said box, a conducting member for operating some of said contacts but insulated therefrom, a conductive latching member mounted on the box and serving to support one sideof said operating member, a cooperative conductive latch member on said cover, and means for grounding both of said latch members and said operating member when the cover is closed.

3. A switch inclosure comprising a box molded integrally from insulating material and a cover therefor likewise integrally molded from an insulating material, cooperating hinge portions being molded integrally on said box and cover, one side of said box having a slot cut therein, contacts of conductive material mounted in said box, a conducting member for operating some of said contact but insulated therefrom, aconductive latching member mounted on the box to close said slot and serve as a support for one side of said operating member whereby the latter is supported wholly by conducting material at one end, a cooperative conductive latch member on said cover, and means for ground ing both of said latch members and said operating member when the cover is closed.

4. A switch inclosure comprising an integrally molded box of insulating material and an integrally molded cover also of insulating material hingedly connected through cooperating hinged portions integrally formed on said box and cover, said box being provided with means to secure the same to a support.

5. A switch inclosure comprising an integrally molded box of insulating material and an integrally molded cover also of insulating material hingedly connected through cooperating hinged portions integrally formed on said box and cover, said box being provided with means to secure the same to a support, a switch operating means therein, and means molded integrally with said cover to lock said operating means in operating position when said cover is closed.

In witness whereof, I have hereunto subscribed my name.

ALBERT P. BALL 

